"ESPN's Dota 2 broadcast is a giant leap for e-sports," Alex Magdaleno wrote. "At a time where professional gaming continues to grow in legitimacy, the collaboration between Valve and ESPN marks one of the first mainstream e-sports broadcasts and a sign of that continued growth."

Dota 2 is a highly competitive multiplayer video game that pits teams of five players against each other to capture or destroy each team's heavily guarded base. Teams from all over the world compete against each other for the biggest prize amount in professional gaming, Forbes reported. The Daily Dot reported that 2013's tournament "broke viewership records" with a high of 1 million viewers during the broadcast, making 2014 the perfect time to begin a mainstream broadcast.

But while the broadcast will be a hallmark for a sport that's mostly gained a following online, Forbes' Eric Kain says the real battle will be fought in viewership and how fans new and old plan to watch.

"Are gamers more likely to watch the Dota 2 tournament on ESPN or its app, or on Twitch?" Kain wrote. "We’re at, or approaching, a crossroads as traditional television and online streaming begin to overlap. A similar confluence is happening with sports and e-sports."

The tournament will be held in Seattle's Key Arena through Monday, and the venue's 10,000 seats sold out in one hour, Forbes reported in April.